A. Field
The present invention refers to a steam automatic dispensing device for preparing hot and/or frothed drinks.
B. Related Technology
Preferably, but not exclusively, the invention is employed as an accessory separated or integrated of the espresso coffee machine for bar, for producing frothed hot milk to be used for instance for preparing cappuccinos.
It is known that, for producing milk froth with espresso coffee machines, the operator uses a container within which he pours a certain amount of milk, inside which he introduced steam through a jet simultaneously shaking the container, so to generate a certain turbulence inside the milk and to add in the environment air needed for producing froth.
The qualities and the quantity of the produced froth depend on the way the milk is shaken and on the amount of steam introduced, and they are therefore linked to the sensibility and experience of each operator. It follows that such features, and then the ones of the cappuccino within which the frothed milk is used, vary from operator to operator and they can be completely unsatisfactory to the client even deemed to be excellent by the operator.
A solution to the problem of how making the quality of the obtained product independent from the operator is the subject of the international patent application WO 01/97668, in the name of the applicant. Such patent application discloses a device essentially consisting of a container within which milk to be heated and to be frothed can be poured, inside which are provided a first duct for introducing steam in milk and a second duct, joined to said first duct, for introducing in milk the air needed for producing froth. The duct for steam dispensing is provided with a radial opening for the exit of steam and the duct for air ends within an axial opening placed in front of said radial opening of the steam duct. This way, the steam dispensing from said radial opening produces a depression that in its turn causes the air suction through the corresponding duct, the steam effusion velocity generates a turbulence at the bottom of milk causing that it is heated and mixed with air and a milk-air-steam mixture is therefore produced directly inside milk, with consequent froth formation.
However effective, the device above illustrated proves to be not much versatile, because it always provides the production of a milk-air-steam mixture and it makes impossible, for instance, the production of hot milk without froth.
Other devices using steam for heating drinks or food are respectively described in the documents U.S. Pat. No. 6,099,878 and FR 2 824 249.
U.S. Pat. No. 6,099,878 discloses a fully automatic, milk inclusive espresso coffee machine which includes coffee bean grinding and brewing apparatus and a milk aeration system which pumps a selection of milk from an internal refrigerator through a choice of aeration processes to a steaming apparatus for heating and further conditioning the milk for joining the brewed coffee liquor. With each beverage production cycle all milk is hygienically either served or returned to its refrigerated reservoir. A process is disclosed which includes pumping milk, all in a refrigerated environment, selectively along a plurality of milk lines one of which may inject air for foaming the milk to a steam delivery line for heating and steaming it and delivering it to a beverage cup. After the desired amount of milk has been delivered, the steam flow continues momentarily to cleanse the line of residual milk. FR 2 824 249 discloses a device for heating food comprising a temperature measurement rod including an agitator section with steam outlets and temperature sensor. A handle is used for stirring. The steam generator feeds the outlets through a flexible tube connected to the rod. An electrical controller is wired to the sensor and steam generator and/or a display unit.